check whether a number is prime number or not in java

/**
 * @author lautturi.com 
 * Java example:determine whether a number is a prime number in java
 */

import java.util.*;

public class Lautturi {
	public static boolean isPrimeNumber(int num) {
		int i, m = 0;
		m = num / 2;
		if (num == 0 || num == 1) {
			return false;
		} else {
			for (i = 2; i <= m; i++) {
				if (num % i == 0) {
					return false;
				}
			}
			return true;
		}
	}

	public static void main(String[] args) {
		for (int num = 0; num < 30; num++) {
			if (isPrimeNumber(num)) {
				System.out.println(num + " is a prime number. ");
			}
		}
	}
}

output:

2 is a prime number. 
3 is a prime number. 
5 is a prime number. 
7 is a prime number. 
11 is a prime number. 
13 is a prime number. 
17 is a prime number. 
19 is a prime number. 
23 is a prime number. 
29 is a prime number.